In the field of printers, fluid firing units of a printhead are designed to fire printing fluid through nozzles in accordance with a voltage which can be applied on the units.
If these fluid firing units remain idle over a long period of time, there is an increasing risk that printing fluid in the fluid firing units becomes dry, thereby blocking these fluid firing units and preventing any further printing operation.
Therefore, the fluid firing units need to be cleaned during a recovery operation to keep the fluid firing units healthy and to ensure they remain operational, in order to maintain a good image quality over the printer's life time.